Thermal properties from membrane of polyamide 6/montmorillonite clay nanocomposites obtained by immersion precipitation method

Morphology and Thermal Characteristics of Polyamide/Monosodium Glutamate Membranes

“…The first local peak is noticed between 90-110 C (region iii), due to evaporation of moisture or formic acid confined within the membrane structure. This behavior is in agreement with the prior studies by Shieh and Chung [28] and Leite et al [29], in which similar peaks were observed for cellulose acetate and polyamide 6 membranes, respectively. The comparison of thermal characteristics of various membranes can be done in terms of parameters critical temperature T c and endothermic heat flow Q c at which moisture=formic acid escapes the membrane [28].…”

Comparative Study of Membranes Obtained from PA6 and PA66/National Clay Nanocomposites

“…To obtain the organoclay (OMMT) a suitable treatment was suitable for the salt, based on the CEC of clay, according to procedure reported in previous studies (Leite et al, 2009;Araujo et al, 2007). To obtain the nanocomposites of polyamide/clay there has been a preparation of concentrates (1:1) in an internal mixer coupled to a torque rheometer from Haake System 90-Büchler, operating at 240°C for polyamide 6 and 260ºC for polyamide 66, at 60 rpm for 10 minutes.…”

“…The mixtures were processed in a counterrotating twin screw extruder coupled to a torque rheometer System 90 from Haake-Büchler at a temperature of 240°C for polyamide 6 and 260ºC for the polyamide 66 in all heating zones and speed of the screws at 60 rpm. Before any processing step, the polyamide materials were dried at 80 ± 5 º C for 24 hours in the vacuum oven before being processed for removal of moisture (Leite et al, 2009). The method of phase inversion by immersion-precipitation technique was used in the preparation of membranes.…”

Hybrid Membranes of Polyamide Applied in Treatment of Waste Water

“…For all the analyzed membranes, there are two endothermic peaks corresponding to the two crystalline phases existing, in approximately, 220 °C related to the α phase and in 210 ºC related to the γ phase. The adding of clay improves the barrier properties of the films, however induces the appearance of γ phase [46][47][48][49] . In Table 1, there are variations in the degree of crystallinity of the nanocomposite membranes when compared with the membrane PA6.…”

“…Probably, the presence of the clay crystalline behavior altered of PA6. However, when small percentages of clay are added to polymer matrices, the degree of crystallinity Xc, increases the nanocomposite which may demonstrate a nucleating effect of the clay 34,35,49 . The SEM images of the top surface and cross section of pure PA6 membranes and their hybrids 1, 3, 5% w/w of MMT, adding 10% w/w CaCl 2 , are shown in figures from 3 to 6.…”